Scroll Compressor Research Articles

Energy saving in six doors walk-in cooler

Two Identical six doors walk-in coolers are installed with the fixed speed compressor and the digital scroll compressor. Both compressors have almost the same cooling capacity of 8 kW at the evaporating temperature of -6.7 °C and the ambient temperature of 32 °C. The heating loads from the envelope, the water bottles, and the air change during the door closing and opening of both coolers are the same. The temperature of the room in front of the cooler doors is controlled at 25 °C. They are set to have a similar average room temperature and a similar cool down. Both units are run 24 h per day for 30 days during which the ambient temperature and the power consumption are recorded. The results show that for Thailand weather, yearly saving is 20% for the digital scroll as compared with the fixed speed compressor.

Compression chamber volume analysis for co-rotating scroll compressors

Within the range of available scroll compressors, the co-rotating configuration has promise to reach lower noise, lighter weight, and higher performance levels. The design and optimisation of such compressors can be simplified if an accurate mathematical model is available to describe and construct their geometry. In this paper, we introduce a model to calculate the volume of gas chambers as a function of scroll rotation angle and other geometrical parameters, over the full course of compression. We have included the effect of dual-arc tip modification on the shape of the scrolls and the discharge chamber to make the model suitable for real scroll geometries. The results can be used for the thermodynamic and fluid mechanic analysis of such devices, where the gas control volume variation needs to be known.

Perfect Balancing Design with Sub-Crank Mechanism in Scroll Compressors

Perfect Balancing Design with Sub-Crank Mechanism in Scroll Compressors

Modeling and simulation analysis of oil-free scroll compressor driven by magnetic force

In order to solve the problems of wear, lubrication and complex structure of digital oil-free scroll compressor, an oil-free scroll compressor driven by magnetic force is proposed in this paper. The new scroll compressor is driven by electromagnetic force, without anti-rotation mechanism and motor, which reduces mechanical contact, so as to achieve the goal of low wear and oil-free. Back pressure device provides variable axial magnetic force to reduce the vibration of the compressor and ensure that the compressor works under the optimum force. The mathematical model of back pressure device and driving force is established and verified by finite element method. The results are in good agreement. The closed-loop step response of the new compressor is simulated. The gas force is decomposed and analyzed. The analysis, calculation and simulation results show that the back pressure device and the driving device meet the requirements of the compressor.

Simultaneous Measurement of Leakage and Friction at Tip Seal in Scroll Compressor

Simultaneous Measurement of Leakage and Friction at Tip Seal in Scroll Compressor

Slap Behavior of Oldham Ring on Scroll Compressor

Slap Behavior of Oldham Ring on Scroll Compressor

Comprehensive Analysis of Geometric Performance of Circular Involute Variable Thickness Scroll Compressor

Comprehensive Analysis of Geometric Performance of Circular Involute Variable Thickness Scroll Compressor

A Quasi-dimensional Numerical Investigation of the Scroll Expander of an Organic Rankine Cycle Unit

Scroll compressors are often used in air conditioning and refrigeration systems thanks to their high efficiency, low noise and vibrations, light weight and high reliability. Scrolls are also widely used as positive displacement expanders in small-scale power generation systems, such as Organic Rankine Cycles (ORCs). In recent years, the research has focused on the development of mathematical models that help to predict the scroll expander performances under different operating conditions. In this work, a quasi-dimensional model of a scroll expander of an Organic Rankine Cycle unit is presented. Such an expander consists of two identical circle involute spirals, with appropriate starting segments. Specifically, the model is able to design the scroll expander geometry with either a “circular cutter” or a “perfect mesh profile” (PMP) approach, which are two of the most common scroll geometry starting segments. As regards the thermo-fluid dynamic aspects, specific sub-models have been used to account for radial and axial leakage, wall heat transfer, intake and exhaust of the working fluid. The model has been validated with available experimental data in order to assess its accuracy and, at the same time, to calibrate the implemented sub-models. The influence of some geometrical parameters on the expander performances has been assessed. In particular, a study of the influence of the wrap geometry is presented. The results show that the circular cutter approach returns better performances at the expenses of a higher mass consumption. Nevertheless, the circular cutter modification returns a higher specific work. Lastly, the influence of one of the PMP parameters on performances has been assessed. The results show a fairly strong dependence of both mechanical power and specific work, suggesting that the global optimization of all geometric parameters of the scroll expander may radically improve its performances.

Study on Leakage Reduction of Three-Dimensional Scroll Compressor

Study on Leakage Reduction of Three-Dimensional Scroll Compressor

A Study of Theoretical Evaluation of Oil Film Pressure between Wraps of Scroll Compressor

A Study of Theoretical Evaluation of Oil Film Pressure between Wraps of Scroll Compressor

Evolution and Future Prospects of Scroll Compressor Technology

Evolution and Future Prospects of Scroll Compressor Technology

On the cut-off angle for the wraps of scroll compressors. An analytical approach

On the cut-off angle for the wraps of scroll compressors. An analytical approach

Calculation Method of Overturning Moment in Asymmetric Type Scroll Compressors

Calculation Method of Overturning Moment in Asymmetric Type Scroll Compressors

Study on energy consumption model of multi-unit air conditioning system with digital scroll compressor

Study on energy consumption model of multi-unit air conditioning system with digital scroll compressor

Design of microcontroller-based decentralized controller board to drive chiller systems using PID and fuzzy logic algorithms

This study deals with designing a decentralized multi-input multi-output controller board based on a low-cost microcontroller, which drives both parts of variable-speed scroll compressor and electronic-type expansion valve simultaneously in a chiller system. This study aims to show the applicability of commercial low-cost microcontroller to increase the efficiency of the chiller system, having variable-speed scroll compressor and electronic-type expansion valve with a new electronic card. Moreover, the refrigerant system proposed in this study provides the compactness, mobility, and flexibility, and also a decrease in the controller unit’s budget. The study was tested on a chiller system that consists of an air-cooled condenser, a variable-speed scroll compressor, and a stepper driven electronic-type expansion valve. The R134a was used as a refrigerant fluid and its flow was controlled by electronic-type expansion valve in this setup. Both variable-speed scroll compressor and electronic-type expansion valve were driven by the proposed hardware using either proportional integral derivative or fuzzy logic controller, which defines four distinct controller modes. The experimental results show that fuzzy logic controlled electronic-type expansion valve and proportional integral derivative controlled variable-speed scroll compressor mode give more robustness by considering the response time.

Numerical analysis and correlations for radial and tangential leakage of gas in scroll compressors

Scroll compressors are positive displacement machines of orbital motion that compress a gas by means of two interfitting spiral-shaped scroll members. Gas leakage is an important source of inefficiency in scroll compressors and it therefore needs to be estimated. Currently, correlations for leakage required in simulation models are based on simplified flow conditions. Thus, a high degree of uncertainty is associated with leakage predictions for the wide range of operating conditions found in actual applications. This paper reports a numerical analysis of radial and tangential leakage in scroll compressors considering different gases, operating conditions and geometries expressed as dimensionless parameters. Numerical models were developed to analyze the aforementioned phenomena in detail, including the geometry of the wraps. Based on the predicted values, correlations for the radial and tangential leakage of gas particularly suitable for comprehensive simulation models were developed and validated through comparison with experimental data and other models available in the literature.

Energetic Assessment of an Electronic and a Thermostatic Expansion Valve for a Variable Capacity Compressor

In this study, a chiller system with an electronic expansion valve (EEV) and a thermostatic expansion valve (TXV) were compared from an energy saving view under variable and fixed speed compressor. The experimental chiller system under study has a variable speed scroll compressor, EEV and TXV, air cooled condenser and auxiliary equipments. The R134a was used in the compressor as a refrigerant. Although in variable speed chiller systems usually EEVs are used, in this study a TXV was also used to compare its performance. The results of the experimental studies show that the chiller system with EEV has 30% lower superheat value and 6% lower power consumption than the chiller system with TXV under variable speed operation. From the fixed speed compressor view, the chiller system with TXV performs 1.7% lower superheat value than the chiller system with EEV and, the chiller system with EEV has 8.5% higher compressor power consumption than TXV.

Influence of the refrigerant charge in an R407C liquid-to-water heat pump for space heating and domestic hot water production

A large number of commercially available domestic heat pumps are being produced without liquid receivers in order to minimize the refrigerant charge. In this type of systems knowing the effect of the refrigerant charge is of prime interest in order to optimize the system performance. This paper presents an experimental study of the influence of the refrigerant charge in an R407C liquid-to-water heat pump for space heating and domestic hot water production. The heat pump consists of a fixed speed scroll compressor, brazed plate heat exchanges and a thermostatic expansion valve. Experimental results are presented for the heating mode of operation at two different water temperatures in the condenser (low and medium temperature applications) with and without domestic hot water (DHW) production in a desuperheater. Results show that an optimum charge that maximized the system COP could be determined. This optimum charge was slightly different when the heat pump was operated for space heating only or for combined space heating and DHW production.

Finite element analysis of new energy vehicle scroll compressor shell under working pressure

The interference design between the mating surface of shell and retainer in new energy vehicle scroll compressor were important parts of the design of the shell assembly. The finite element analysis of static structure was used to analyze the strength of shell and the deformation value of the mating surface under the working pressure, and minimum surplus were used to analyze whether the matching surface surplus design meet the design requirements. An analytical method was provided for the design of new energy automobile scroll compressor shell by static structure analysis of shell and the interference of mating surface.

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